The present invention relates to a recording media drive having a circuit board mounted thereon and suitable for a hard disk drive (hereinafter referred to as “HDD”) and other electronic devices, the circuit board mounting thereon electronic parts adapted to operate at mutually different voltages.
Devices using various types of media such as optical disks and magnetic tapes are known as recording media drives provided inside or outside information processing apparatuses. Among them, hard disk drives (HDDs) have become popular as storage devices for computers to such an extent that they are one of the storage devices indispensable for today's computers. Further, not limited to computers, their application is widening more and more due to the superior characteristics with the advent of moving picture recording/reproducing devices, car navigation systems, digital cameras, removable memories used therein and so on.
Each magnetic disk used in HDDs has a plurality of tracks formed concentrically and each track is partitioned into a plurality of sectors. In each sector, sector address information and user data are stored. Either data write to a sector or data read from the sector is enabled by a magnetic head which accesses the desired sector according to the sector address information. A signal read out from a magnetic disk through data read operation is subjected to waveform shaping, decoding processing and other prescribed signal processing by a signal processing circuit on a HDD circuit board before being transmitted to the host. Likewise, data transferred from the host is subjected to prescribed signal processing by a signal processing circuit and then written to the magnetic disk.
The circuit board is supplied with a supply voltage from a host device (hereinafter referred to as “host”) such as a desktop or notebook type personal computer provided with the HDD. For the purpose of reducing power consumption and reducing unnecessary electromagnetic radiation, the operating voltage of the host is changing from the conventional 5V to a lower level of 3V to 3.3V. Therefore, many information processing apparatuses such as PC available recently have a voltage supply segment of 3.3V.
On the other hand, the circuit board of the HDD also carries an electronic part such as a logic circuit which operates at 3.3V. However, a conventional host and HDD supplied with electric power from the host have only power pins for the supply of 5V and 12V and thus it has so far been impossible for the HDD to be supplied with 3.3V from the host. To avoid this inconvenience, the conventional HDD circuit board is provided with, for example, a sub-power segment for the conversion of 5V to 3.3V in order to activate an electronic part mounted on the circuit board and adapted to operate at 3.3V (see Patent Document 1, Japanese Patent Laid-Open No. Hei 7(1995)-253831).
According to the technique described in Patent Document 1, a DC-DC converter as a sub-power segment and a fuse as a protective means are provided on a circuit board. A supply voltage of 5V supplied through a power connector is converted to 3.3V by the DC-DC converter and this electric power is fed to an electronic part which operates at 3.3V.
As an interface provided for data transmission between HDD and host, there usually is employed SCSI (Small Computer System Interface) or ATA (AT Attachment) interface. Particularly, ATA interface is utilized in many computers from the standpoint of improving the interface function and reducing the cost. It is also widely utilized as an interface of other types of storage devices such as, including optical disk storage devices.
With the recent demand for improvement in recording density and performance of storage media, the request for the data transmission speed of ATA interface is becoming more and more strict. To meet such a strict request, an ATA interface (Serial ATA) using serial transmission has been proposed instead of the conventional parallel transmission method.
The standard of Serial ATA is being established by “Serial ATA Working Group.” In comparison with the conventional Parallel ATA, Serial ATA is high in transfer speed and permits the reduction in size of connector cable, so that a thermal design of the entire system is also improved.
At present, mother boards conforming to Serial ATA Standard are being supplied from plural venders and so are HDDs conforming to SATA Standard from plural manufacturers, and thus both Parallel ATA and Serial ATA are mixed on the market. In “Serial ATA II: Extensions to Serial ATA 1.0 Specification” already released, there are adopted several techniques not found in the conventional Parallel ATA.
For example, in Parallel ATA, the use of only 5V and 12V is permitted, while in Serial ATA the use of 3.3V is permitted in addition of 5V and 12V. Therefore, Serial ATA is provided with a connecting pin for the supply of 3.3V. Thus, for the connector of an HDD conforming to Serial ATA Standard, there is provided a connecting pin so as to be supplied with 3.3V.